10,218 results for ResearchCommons@Waikato

  • Correlating tephras and cryptotephras using glass compositional analyses and numerical and statistical methods: review and evaluation

    Lowe, David J.; Pearce, Nicholas J.G.; Jorgensen, Murray A.; Kuehn, Stephen C.; Tryon, Christian A.; Hayward, Chris L. (2017)

    Journal article
    University of Waikato

    We define tephras and cryptotephras and their components (mainly ash-sized particles of glass ± crystals in distal deposits) and summarize the basis of tephrochronology as a chronostratigraphic correlational and dating tool for palaeoenvironmental, geological, and archaeological research. We then document and appraise recent advances in analytical methods used to determine the major, minor, and trace elements of individual glass shards from tephra or cryptotephra deposits to aid their correlation and application. Protocols developed recently for the electron probe microanalysis of major elements in individual glass shards help to improve data quality and standardize reporting procedures. A narrow electron beam (diameter ~3-5 μm) can now be used to analyze smaller glass shards than previously attainable. Reliable analyses of ‘microshards’ (defined here as glass shards <10 μm) can be subject to significant element fractionation during analysis, but the systematic relationship of such fractionation with glass composition suggests that analyses for some elements at these resolutions may be quantifiable. In undertaking analyses, either by microprobe or LA-ICP-MS, reference material data acquired using the same procedure, and preferably from the same analytical session, should be presented alongside new analytical data. In part 2 of the review, we describe, critically assess, and recommend ways in which tephras or cryptotephras can be correlated (in conjunction with other information) using numerical or statistical analyses of compositional data. Statistical methods provide a less subjective means of dealing with analytical data pertaining to tephra components (usually glass or crystals/phenocrysts) than heuristic alternatives. They enable a better understanding of relationships among the data from multiple viewpoints to be developed and help quantify the degree of uncertainty in establishing correlations. In common with other scientific hypothesis testing, it is easier to infer using such analysis that two or more tephras are different rather than the same. Adding stratigraphic, chronological, spatial, or palaeoenvironmental data (i.e. multiple criteria) is usually necessary and allows for more robust correlations to be made. A two-stage approach is useful, the first focussed on differences in the mean composition of samples, or their range, which can be visualised graphically via scatterplot matrices or bivariate plots coupled with the use of statistical tools such as distance measures, similarity coefficients, hierarchical cluster analysis (informed by distance measures or similarity or cophenetic coefficients), and principal components analysis (PCA). Some statistical methods (cluster analysis, discriminant analysis) are referred to as ‘machine learning’ in the computing literature. The second stage examines sample variance and the degree of compositional similarity so that sample equivalence or otherwise can be established on a statistical basis. This stage may involve discriminant function analysis (DFA), support vector machines (SVMs), canonical variates analysis (CVA), and ANOVA or MANOVA (or its two-sample special case, the Hotelling two-sample T² test). Randomization tests can be used where distributional assumptions such as multivariate normality underlying parametric tests are doubtful. Compositional data may be transformed and scaled before being subjected to multivariate statistical procedures including calculation of distance matrices, hierarchical cluster analysis, and PCA. Such transformations may make the assumption of multivariate normality more appropriate. A sequential procedure using Mahalanobis distance and the Hotelling two-sample T² test is illustrated using glass major element data from trachytic to phonolitic Kenyan tephras. All these methods require a broad range of high-quality compositional data which can be used to compare ‘unknowns’ with reference (training) sets that are sufficiently complete to account for all possible correlatives, including tephras with heterogeneous glasses that contain multiple compositional groups. Currently, incomplete databases are tending to limit correlation efficacy. The development of an open, online global database to facilitate progress towards integrated, high-quality tephrostratigraphic frameworks for different regions is encouraged.

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  • An Investigation into Establishing (Motivating) Operations

    Jackson, Surrey Merryn Kate (2017)

    Doctoral thesis
    University of Waikato

    Motivating Operations (MOs) are a fundamental concept in behavioural psychology. Despite this, empirical research into MOs is lacking. The overall aim of this thesis is to contribute to the experimental literature base for MOs. Experiment 2.1 used an already published video analysis methodology to assess the morphology of food motivated pecks made to a computer screen by hens, after the hens had been trained to emit the peck using either an autoshaping or handshaping procedure. The intention of this was to then be able to use the video analysis to assess the effect of altering two MOs related to two different reinforcers (e.g., food and water) at one time, on morphology. The study showed that both methods produced similarly formed pecks despite the variability inherent in the handshaping procedure. It was then concluded it is the nature of the reinforcer that gives rise to morphology not the autoshaping procedure per se which gives rise to a particular form of elicited responses. The aim of Experiment 3.1 and 3.2 was to develop a procedure for restricting access to water in laying hens, in order to motivate them sufficiently to respond for water reinforcers. Experiment 3.1 assessed the effect that gradually decreasing time and amount of water access had on food-restricted hens’ water consumption and health. It was found that hens could be restricted to one hr access of water (restricted to the maximum amount that hens would consume when access was ad libitum) without adverse effects to health being apparent. However, when the hens were subsequently exposed to FR schedules with a low response requirement in Experiment 3.2, they did not respond consistently. This indicated that the level of restriction was insufficient to motivate responding and this finding, combined with the difficulty of obtaining ethical approval, meant that the proposed experiments utilising water deprivation as an MO had to be abandoned. Experiment 4.1 used the autoshaping paradigm to assess the acquisition of food motivated pecks to a stimulus, at two different levels of bodyweight (75% and 95%). An infra-red screen was used to analyse performance separately from learning effects by examining activity levels (location and amount of pecks). It was found that that higher numbers of effective pecks were made by hens maintained at 75% free-feeding bodyweight than hens maintained at 95% (different MO conditions). There were also higher levels of ineffective pecks in the 75% group. Experiment 5.1 investigated relative preference for stimuli correlated with different MO conditions: high deprivation (no pre-feeding), or low deprivation (pre-feeding), when subjects were maintained at either 75% or 95% of free-feeding bodyweight. The results showed that 6/10 hens demonstrated an increased preference for the stimulus paired with high deprivation conditions (no pre-feeding) when measured by log ratios of responses, and had faster response rates on this stimulus. Overall, the 75% bodyweight hens had faster response rates than the 95% hens (as in Experiment 4.1), and 8/10 hens responded faster on the stimulus that was paired with no pre-feeding. It was also found, as per Experiment 4.1, that higher numbers of effective pecks were made by hens maintained at 75% free-feeding bodyweight than hens maintained at 95% (different MO conditions). Experiments 6.1 and 6.2 extended the findings of the thesis thus far in that concurrent VI VI schedules were used to assess the effect of bodyweight and pre-feeding as MOs on steady state responding. In total 16 conditions were run exposing hens to three different VI pairs: VI-12, VI-60 (5:1); VI-20, VI-20 (1:1); and VI-60, VI-12 (1:5). Bodyweight values of 85%, 95%, 100%, and 85% with pre-feeding of 40 cc wheat delivered 40 minutes prior to experimental sessions were manipulated between hens finishing a series of the three VI pairs. It was found that 4/6 hens had higher absolute and relative response rates when bodyweight was made lower. For 3/6 of these hens, increasing bodyweight increased sensitivity as measured by the parameter a; this was more distinct when the Generalised Matching Law was applied to response rather than time locations for these hens. Frequency distributions of IRTs showed that for the hens that tended to show increasing sensitivity as bodyweights increased there were more IRTs in bins greater than 0.4 s. This was reflected on the log-survivor plots as the limbs were shallower when bodyweights were higher, indicating that more between-bout responses were occurring. It was also found that pre-feeding increased sensitivity as measured by the parameter a for all hens; this was more noticeable when the GML was applied to response rather than time allocations. Although overall response rates tended to resemble those for the 85% bodyweight condition and remain higher than the 95% and 100% bodyweight conditions, the distribution of left and right response rates showed that hens matched better to the prevailing reinforcer rates when they were pre-fed, than when they were not pre-fed. Overall, the main findings were: (1) that reducing bodyweights increased amounts of species-specific behaviour; and (2) that reducing bodyweight causes increases in response rate. These findings could explain why changes in preference for stimuli paired with high levels of deprivation are observed during SDVL procedures, and why increased sensitivity to available reinforcement at lower levels of deprivation found in studies utilising the GML have been observed in previous studies. These findings contribute to the empirical data informing the behavioural treatment of motivation and have applied implications. Reinforcement and punishment procedures such as extinction or differential reinforcement of alternative behaviours may no longer be necessary when MOs are manipulated.

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  • Tendency toward negative correlations for positively-skewed independent random variables

    Bardsley, W. Earl (2014)

    Journal article
    University of Waikato

    Hydrological variables often display positive skewness, with means exceeding medians. Even when two such variables are independent, there is a more than 50% chance that a bivariate random sample will yield a negative value of the Pearson product-moment linear correlation coefficient r. Simulations from inverse Gaussian distributions suggest that this effect is small and unlikely to have any effect on significance tests of r if two skewed variables are in fact independent. However, a high frequency of negative sample correlations in a multi-site hydrological study could result in an incorrect deduction that some weak but widespread physical process is in operation.

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  • Temporal dynamics of microbial communities in geothermal hotsprings of the Taupo Volcanic Zone

    Lowe, Caitlin Louise (2017)

    Masters thesis
    University of Waikato

    Few studies of microbial biogeography address temporal variability in physicochemical conditions and communities in geothermal environments. Here we examine the temporal variability of 43 chemical analytes, temperature and pH in association with microbial community composition of 69 water samples collected bimonthly from 12 hotsprings of the Taupo Volcanic Zone between December 2015 and October 2016. Communities and physicochemical parameters were characterized using a combination of next generation Ion Torrent sequencing (16S rRNA), UV-spectrometry, ICP-MS, FIA and gas chromatography. Using correlation association tests, significant physicochemical changes (P<0.05) were correlated with temporal variations in microbial community composition in six of the target hotsprings. Of these six hotsprings, temperature and pH were the most influential variables associated with community changes and commonly covaried with the Aquificae, Deinococcus-Thermus and Proteobacteria at four sites. Downstream effects of rainfall using rainfall and geothermal bore water datasets could be linked with physicochemical and microbial community changes during the winter months at two of these sites. This study contributes to our understanding of geothermal microbial dynamics in stable and variable geothermal environme nts, and highlights that geothermal hotsprings are not isolated from their surrounding environment.

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  • Effects of Drying Conditions on Protein Properties of Blood meal

    Damba, Chawangwa (2017)

    Masters thesis
    University of Waikato

    Blood meal is a by-product of the meat industry produced through drying of animal blood. It contains about 85 wt.% proteins. Drying has been used as a method to preserve biomaterials and involves lowering of the water activity of biomaterials. The purpose of this research was to study the drying kinetics of producing blood meal in an oven dryer, to evaluate suitable drying models for describing the drying process and to determine the effects of drying conditions on the physio-chemical properties of blood meal. Moisture content and drying rates were determined by drying coagulated blood at different temperatures (60 °C, 100 °C and 140 °C) for a constant period of 24 hours. The initial moisture content of coagulated blood was about 60.7 wt% on a wet basis. A drying temperature of 140 °C was found to be the optimal for routine moisture determination for coagulated blood as equilibrium moisture was achieved within 24 hours period. A constant drying rate period was not observed in any of the conditions tested, and the initial increasing rate period as followed by a short transition phase prior to the falling-rate period. Thus, moisture removal from the coagulated blood was governed by a diffusion-controlled process. The experimental drying data for coagulated blood was used to fit the Lewis, Page, Modified Page, Logarithmic and Henderson and Pabis models and the statistical validity of models tested were determined by non-linear regression analysis. The Page model had the highest R² (0.9999) and lowest χ² (0.0001) and RMSE values. This indicated that Page model adequately described the oven drying behaviour of coagulated blood. Blood meal samples were produced by drying coagulated blood at different temperatures (60 °C, 100 °C, 140 °C) to varying moisture contents (5 %, 10 % and 15 %). A drop penetration test using water and/or sodium dodecyl sulphate dissolved in water were used to determine the wettability of the samples produce while thermal analysis techniques such as Thermo-Gravimetric Analysis (TGA), Differential Scanning Calorimetry (DSC) and Dynamic Mechanical Analysis (DMA) were used to investigate the thermal properties of bloodmeal. X-ray scattering was used to investigate conformational changes in blood meal proteins during drying. Drying conditions had substantial effects on both physicochemical and thermal properties of blood meal. It was established that drying temperature had a more significant effect on the wettability of blood meal than the final moisture content. However, the final moisture content had larger contribution to the thermal stability of blood meal than drying temperature. Blood meal produced at 60 °C to 15% moisture content was the most stable sample while blood meal produced at 140 °C to 10% moisture content was the least stable. Protein denaturation was observed at 92 °C to 122 °C, depending on moisture content and drying temperature. DMA results revealed that different relaxations occurred when drying coagulated blood. A dry glass transition temperature for samples was observed between 219 °C - 226.8 °C. This suggested that bound water does not act as plasticiser in blood meal. Glass transitions observed in DSC were therefore, considered more accurate and reliable for blood meal samples containing moisture. Drying of coagulated blood was observed to have drastic effect on the structural arrangement of coagulated blood in XRD. Increase in moisture content was observed to have an effect on the β-sheets structure of samples dried at 60 °C and 100 °C. Since bloodmeal produced at 60 °C and 100 °C did not show complete denaturation of proteins, future thermoplastic processing should consider blood meal produced within this temperature range for improved properties.

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  • The Accountability of New Zealand's Charities: Meeting the Needs of Charity Stakeholders through Information Disclosure

    Dimitrov, Dara Katie (2017)

    Doctoral thesis
    University of Waikato

    For decades, New Zealand’s charity sector has been able to operate, unfettered by regulation and with low levels of accountability. For this reason, gaining any information from charities about the work they do has been historically difficult, because charities have not been required to provide any reports. The New Zealand government sought to increase the accountability from the charity sector with the introduction of the Charities Act (2005) and basic reporting requirements, but ultimately, the accountability from the sector continues to be an issue. With limited charity disclosure literature in the New Zealand context, and no information disclosure practice model to guide New Zealand’s charities, the current provision and the quality of the information disclosures from charities are low, leaving the information needs of charity stakeholders unmet. The overall aim of this investigation is to improve the accountability from New Zealand’s charities by developing a charity information disclosure practice model from a charity stakeholder perspective. This was achieved by three main objectives: 1. To develop a qualitative disclosure index from the perspective of charity stakeholders 2. To assess the extent and quality of the information disclosure made by thirty registered charities 3. To make recommendations to improve the accountability by New Zealand’s charity sector To achieve this purpose, a disclosure index, which contained 136 information items was created with the assistance of 86 charity stakeholders. The index was then applied to three publications from thirty charities that were randomly selected from the Charity register. The three publications used in this investigation are the Charity register, the charity’s website and the charity’s annual report/annual review. The collected data was then quantified and analysed to determine the extent and the quality of the information disclosures from the charities. The investigation findings indicated that the current level of charity disclosures was poor both in extent and quality and that there was an information gap between the expectations of charity stakeholders and the actual disclosure practices of the charities. It was found that the top-performing information items were the mandated and the best-practice information items were either missing or inadequately disclosed. No charity within the sample managed to achieve an index score of 50%. The annual return summary found on the Charity register was the best disclosure document for both financial and non-financial information items from a charity stakeholder perspective. However, this document, along with the other publications still lacked sufficient detail to be useful for a charity stakeholder. To improve the accountability of the New Zealand’s sector, it is recommended that the New Zealand Parliament look at expanding the current annual return summary to include information items more relevant to charity stakeholders. Finally, it is recommended that the charities should be compelled to produce an annual report and use the disclosure index created by the charity stakeholders in this investigation to improve their current information disclosures.

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  • Moisture Associated Microbial Communities in Antarctic Dry Valley Soils

    Anderson, Rachelle (2017)

    Masters thesis
    University of Waikato

    Climate change is having a dramatic impact on the natural environment and is one of the most imminent and important issues of the 21st century. With limited vegetation and few large terrestrial organisms, Antarctica offers a unique opportunity to understand the impact of abiotic, climatic factors on microbial ecosystems (free of many of the confounding biological variables in more complex systems). Recent in situ studies indicate that microbial communities within Antarctic soils may respond to environmental changes within far shorter time frames than originally believed. In a landmark study, Tiao et al. (2012) investigated the rate at which microbial communities responded to a unique soil modification experiment. To this end, a mummified seal carcass (dated at 250 years) was shifted from its original site in Miers Valley, to a new, geomorphically similar site in close proximity. Remarkably, increased microbial biomass, decreased biodiversity, and shifts in the microbial community composition were observed within just two summers. While the seal carcass altered the underlying soil’s nitrogen and organic carbon content, pH, and conductivity; statistical analysis revealed that none of these physicochemical changes could satisfactorily explain the changes in the microbial community. Instead the data suggest that the changes observed may have been caused by physical, abiotic factors induced by the seal carcass (i.e. increased and more stable relative humidity (RH), reduced UV exposure, and reduced daily temperature fluctuations). However, due to the un-replicated, observational nature of the study, this is merely speculation. In order to verify these findings and resolve the drivers of the microbial community changes observed, a controlled, in situ experiment was designed to replicate the abiotic effects of the seal carcass (stabilise temperature, reduce UV exposure, and increase and stabilise RH in the underlying soil). To do this, overturned or upright black and translucent plastic trays were set up on undisturbed regions of Antarctic Dry Valley soil; soil samples were taken every January for a five-year period; and Ion Torrent sequencing of 16S rRNA gene amplicons was used to assess changes in the microbial community composition and structure. However, based on RH data and visual observations of the site it would appear that the tray experiment was unknowingly set up in either a flat, low lying area where moisture accumulated; or in a subsurface water track. Due to the constant high moisture content within the soil on which the experiment was deployed, the effect of the tray treatments on the local environment (i.e. RH and temperature) was negligible. The microbial community composition in the tray treatment experiment stayed quite consistent across all years and treatments, however there was a significantly greater abundance of Cyanobacteria/ Chloroplasts in the translucent overturned (TO) treatment than in the black upright (BU) or black overturned (BO) treatments. Interestingly, the moist tray treatment soil had a greater relative abundance of Cyanobacteria/ Chloroplasts, Proteobacteria, and Bacteroidetes than the drier seal control site, in keeping with the observations of other studies investigating microbial community composition within wet environments. These findings hint at the importance of small-scale topographic factors in microbial community structure, and/or highlight the potential of using microbial community composition as a bio-indicator of hidden water tracks.

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  • Antimicrobial Peptides in Jawed and Jawless Vertebrates

    Gibbons, Olivia Robyn (2016)

    Masters thesis
    University of Waikato

    Antimicrobial peptides (AMPs) are a major part of the innate immune defence system which shows a broad spectrum of activity, defending the host against invading microbes. The aim of this work was to identify the AMPs present in yellowtail kingfish (Seriola lalandi) and pouched lamprey (Geotria australis) and use molecular techniques to fully sequence their cDNA and quantify their expression in adult individuals. Using bioinformatic approaches candidate AMP genes were ascertained from available S. lalandi and G. australis RNA-seq transcriptomic databases, obtained from various tissues. Selected AMPs were chosen to have their full cDNA sequence amplified using RACE-PCR, which were then cloned and sequenced. Complete cDNA sequences were obtained for S. lalandi hepcidin and moronecidin, whereas attempts to complete the G. australis defensin-like cDNA were unsuccessful. Comparison of the S. lalandi hepcidin and moronecidin protein sequences with proteins already characterised in other fish showed good homology and conservation of important features. In addition, specific primers were designed to examine the expression levels of S. lalandi hepcidin and moronecidin in gill, liver or spleens of three fish. Analysis showed hepcidin expression to be highest in liver tissues, whereas moronecidin expression was highest in the gills and spleens. This study provides a comprehensive overview of the AMP genes present in S. lalandi and G. australis and some initial characterisation of S. lalandi hepcidin and moronecidin, which will permit the development of future research applications. Overall, characterising AMP genes in jawed and jawless vertebrates is vital for economical and successful fish farming, while also providing possible therapeutic benefits associated with AMP research in biomedicine and disease in wild fish stocks.

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  • Repetitive Transcranial Magnetic Stimulation: A Call for Better Data

    Wilson, Marcus T.; St George, Lynley (2016)

    Journal article
    University of Waikato

    Repetitive Transcranial Magnetic Stimulation (rTMS) is increasingly used to treat stroke, Parkinson's disease and depression (Fregni et al., 2005; Loo and Mitchell, 2005; Hallet, 2007; O'Reardon et al., 2007; Ridding and Rothwell, 2007). rTMS uses bursts of magnetic pulses to change the excitability and connection strengths of cortical neurons. However, the evidence to inform clinical application is highly inconsistent (Thut and Pascual-Leone, 2010; Hamada et al., 2013) and substantially based on trial and error. Systematic theory is lacking. Typically, in rTMS research, measurements of motor-evoked potential (MEP) are made, often in terms of the strength of the MEP and the length of the cortical silent period that follows. However, the MEP is probably a poor and certainly an indirect measure of changes in the brain (Nicolo et al., 2015), clouding our understanding of rTMS mechanisms. In practice, therefore, particular amplitudes and timing of pulses in an rTMS sequence are selected because they show promise in small subsets of people. However, even basics such as the sign of any change in the outcome measure (e.g., does the MEP increase or decrease?) is debated. Many results show a wide spread in responses. It has become common to talk about “responders” and “non-responders” although evidence for a binary distinction in these two groups is lacking—in reality there is usually a continuum of response often including potentiation in some and depression in others (Nettekoven et al., 2015). Moreover, Héroux et al. (2015) provide evidence that the irreproducibility of results may be due to small sample sizes, unscientific screening of subjects and data, and selective reporting of results.

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  • The rewards of professional change: Two primary school teachers’ experiences of transforming outdoor education.

    Cosgriff, Marg (2017)

    Journal article
    University of Waikato

    Embarking on and sustaining professional change is often a challenging process for educators. This is particularly so within a broader context of rapid (r)evolution in curriculum, pedagogical and assessment-related developments in the compulsory school sector in Aotearoa New Zealand over the past decade. Teachers’ and school leaders’ accounts of professional learning and change in recent issues of this journal have suggested it can be both risky and rewarding, with a range of impacts and outcomes for all involved. In this paper I pick up on the notion of the possible rewards of professional change, drawing on the experiences of two generalist primary school teachers engaging in curriculum and pedagogical change in outdoor education within the Health and Physical Education learning area. Specifically, the contributions of outdoor-based learning in a local bush reserve to teachers’ own sense of personal wellbeing and rejuvenated sense of professional identity are explored. Here I speculate about the potentially renewing components of professional change in outdoor education in HPE for teachers themselves.

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  • Intermittency, nonlinear dynamics and dissipation in the solar wind and astrophysical plasmas

    Matthaeus, Willam H.; Wan, Minping; Servidio, Sergio; Greco, A.; Osman, Kareem T.; Oughton, Sean; Dmitruk, Pablo (2015)

    Journal article
    University of Waikato

    An overview is given of important properties of spatial and temporal intermittency, including evidence of its appearance in fluids, magnetofluids and plasmas, and its implications for understanding of heliospheric plasmas. Spatial intermittency is generally associated with formation of sharp gradients and coherent structures. The basic physics of structure generation is ideal, but when dissipation is present it is usually concentrated in regions of strong gradients. This essential feature of spatial intermittency in fluids has been shown recently to carry over to the realm of kinetic plasma, where the dissipation function is not known from first principles. Spatial structures produced in intermittent plasma influence dissipation, heating, and transport and acceleration of charged particles. Temporal intermittency can give rise to very long time correlations or a delayed approach to steady-state conditions, and has been associated with inverse cascade or quasi-inverse cascade systems, with possible implications for heliospheric prediction.

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  • Temperature and Moisture Sensitivity of Soil Microbial Respiration in Adjacent Irrigated and Non-Irrigated Soils

    Petrie, Olivia Jane (2017)

    Masters thesis
    University of Waikato

    Irrigation is a commonly used management practice that is crucial for increasing plant growth and production, especially in areas prone to drought such as the Canterbury region of the South Island, New Zealand. Historically, irrigation was thought to increase soil carbon content due to increased production, however recent studies have shown that irrigation causes a loss of soil carbon (C). One possible mechanism for the C loss is an increase in soil microbial respiration under irrigation. The added soil moisture under irrigation releases microbial moisture limitations and enables soil microbes to access more C, therefore increasing respiration and decreasing soil C content. Soil microbial respiration also fluctuates seasonally. Irrigation changes the inherent seasonal effect by increasing soil moisture content during the hottest part of the year, therefore increasing soil microbial respiration rates. In this thesis soil samples were collected from 13 paired irrigated and non-irrigated sites in Canterbury and two sites at Rangiriri in the Waikato region of the North Island. The sites in Canterbury were sampled once while the sites at Rangiriri were used for a seasonal analysis and were sampled twice. Soil samples were wet to five different moisture contents and incubated on a temperature gradient block for five hours. MMRT curves were then fitted to the respiration data obtained from incubation and the temperature optima (Topt), temperature inflection point (Tinf) and change in heat capacity (ΔCp‡) were calculated. The absolute respiration rates at 10°C (R10) and 20°C (R20) were also calculated. Irrigation had a significant effect on soil microbial respiration in the Canterbury soils but not the Rangiriri soils. In Canterbury, the Topt and Tinf were higher in the irrigated soils by 8.8°C and 7.6°C respectively while the R10 and R20 were both nearly 50% higher in the non-irrigated soils and all differences were statistically significant. There was no difference between treatments in any of the parameters measured in the Rangiriri soils. The difference in temperature sensitivity and absolute respiration rate in the Canterbury soils was thought to be due to the soil microbes under irrigation decomposing less readily available soil C which has a higher temperature sensitivity and leads to a reduced respiration rate. Another possible explanation for the differences in temperature sensitivity and absolute respiration rate was that there had been a shift in soil microbial community structure between the two treatments and this should be further investigated.

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  • Characterisation of Food Intake and Expression of Feeding-Related Genes in The VPA Rat Model of Autism Spectrum Disorder

    Laloli, Kathryn (2017)

    Masters thesis
    University of Waikato

    Autism spectrum disorder (ASD) is a neurodevelopmental disorder affecting roughly 1% of the global population. Aberrant food selectivity (AFS) is a common comorbid symptom of ASD which can result in nutritional deficiencies, increased parental stress and reduced quality of life. However, alarmingly little research has been conducted investigating the nature and the underlying neurophysiological mechanisms of AFS in ASD. This study attempts to determine whether the VPA rat model of ASD exhibits AFS when presented with various diet types. These include standard chow and water, palatable sweet tastants (sucrose, saccharin and complex liquid diet) and finally palatable high fat milks. The mRNA expression levels of oxytocin, oxytocin receptor, dynorphin and kappa-opioid receptor were then determined. These genes have previously demonstrated to be involved in both feeding and social behaviours. The VPA rats were found to consume less standard chow and water, yet increased intake of the sweet tastants was observed. Additionally, in the VPA rats’ oxytocin expression in the hypothalamus was increased, as was dynorphin expression in the hypothalamus and brainstem. Increased expression of the anorexigenic oxytocin may have resulted in the decreased intake of chow and water, and could potentially be a result of increased leptin or melanocortin levels. However, increased dynorphin expression may be responsible for the increased intake of the palatable sweet tastants, via inhibition of proopiomelanocortin or neuropeptide S. The development of effective treatments for AFS in ASD requires an understanding of the underlying neurological mechanisms. This research provides the first evidence of AFS and elevated oxytocin and dynorphin expression in the VPA rat model of ASD, thus paving the way for further research in this area.

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  • Secondary Traumatic Stress and Vicarious Posttraumatic Growth in New Zealand Clinical Psychologists: The Consequences of Working with Traumatised Clients

    Stapleton, Madeleine (2017)

    Masters thesis
    University of Waikato

    Clinical psychologists who provide trauma treatment are vicariously exposed to their clients’ traumatic experiences. The responsibility of clinical psychologists to practise both effectively and safely makes assessing the negative and positive psychological consequences of vicarious exposure to trauma imperative. If provisions are not put in place to prevent the negative psychological consequences and facilitate the positive psychological consequences, then detrimental outcomes may arise for the clinician, their clients, and the organisation that they work for. The present study was designed to assess the experience of secondary traumatic stress (STS) and vicarious posttraumatic growth (VPTG) in clinical psychologists who work with traumatised clients in New Zealand. The purpose of this study was to identify the factors that were related to these phenomena, including the level of vicarious exposure to trauma (years working as a clinical psychologist, hours per week working with traumatised clients, and percentage of traumatised clients on caseload), posttraumatic cognitions, secondary trauma self-efficacy (STSE), perceived social support, and engagement in self-care activities. Seventy-two clinical psychologists completed the online survey. Significant relationships were found between the main variables in this study: STS correlated positively with posttraumatic cognitions and VPTG correlated positively with self-care. Non-hypothesised significant relationships were also found. Posttraumatic cognitions correlated significantly with hours per week working with traumatised clients, STSE, perceived social support, and self-care. Additionally, self-care correlated significantly with perceived social support. The results of this study suggest that clinical psychologists who experience more posttraumatic cognitions following vicarious exposure to trauma may be more likely to experience STS. The results also suggest that those clinical psychologists who engage in more self-care activities may be more likely to experience VPTG. As the majority of the proposed hypotheses were not supported, it appears that the factors thought to be related to STS and VPTG may not be as pertinent as previous research indicates. Overall, the results suggest that there may be other factors not explored in this study that may influence the experience of STS and VPTG. As discrepant results were found in this study, future research should continue to investigate the factors that are related to STS and VPTG in clinical psychologists. Investigation into the ways in which posttraumatic cognitions following vicarious exposure to trauma can be prevented, or reduced, would also be beneficial, as would investigation into the specific self-care activities that are related to VPTG. Future research could also investigate the barriers that may prevent clinical psychologists from engaging in self-care. Taken together, this study provides insight into the factors that are related to STS and VPTG, and importantly, identifies how STS may be prevented and VPTG may be facilitated.

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  • Effective, accountable and inclusive institutions? An analysis of the Chevron v. Ecuador (II) investment arbitration and the Lago Agrio environmental justice movement

    McGiven, Timothy Clyde (2017)

    Masters thesis
    University of Waikato

    The international investment agreement regime, one of the more obscure global institutions, has a significant impact upon how states, local governments and communities develop. Many investment agreements include investor-state dispute settlement (ISDS) mechanisms, which seek to protect investors from unjust expropriation by host states. Yet, the implications of such a mechanism for fulfilling the vision of the United Nation’s Sustainable Development Goals (SDGs) have never been studied. This thesis examines the ISDS mechanism by conducting a case study of the Chevron v. Ecuador (II) [CvE2] investment arbitration. The thesis analyses case documents such as hearing transcripts, decisions and submissions to identify the discourses at work within the arbitration; determine the implications of such discourses for processual developments; and explore how such processes influence the space afforded to those nongovernmental organisations and environmental justice groups affected by the arbitration. The research utilises an analytical framework informed by critical development theory and environmental justice theory, to demonstrate that the CvE2 arbitration is dominated by an exclusive discourse that prioritises a strict adherence to international investment law, to the exclusion of other principles such as those of international human rights law and environmental law. The dominance of such a discourse reduces the legitimacy of the institution and its rulings for many key stakeholders. The findings also reveal that marginalised stakeholders, such as environmental organisations representing indigenous communities, were refused access to the arbitrations though they were materially affected by the claims, and additionally, were denied consideration - whereby the material impact of the ruling upon the stakeholder group was deemed irrelevant to the proceedings. The findings provide evidence that ISDS, in its current form, is incompatible with the United Nation’s goal for ‘effective, accountable and inclusive institutions’ (United Nations Development Programme, 2016, p. 1). This thesis contributes to the scholarship on environmental justice and environmental policy through its analysis of the implications of arbitration mechanisms embedded in international investment regimes for environmental justice claims and, more broadly, the goal of sustainable development. The thesis highlights the need for further research into investor-state investment arbitrations and provides evidence that significant reform is necessary in order for the institution to be reconciled with the SDGs.

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  • You and me and shame

    Gillanders, Leah Esme (2017)

    Masters thesis
    University of Waikato

    This research project investigated the effects of bringing an as-yet-untold story of shame to a narrative therapy counselling conversation. The researcher, who became the client, invited a narrative practitioner to join her in three conversations, a counselling conversation and two interpersonal process recall conversations. The data generated from these conversations as well as the personal research diary kept by the researcher are woven together as research findings, presenting a layered, journeyed account of the movement experienced by the researcher. This study noticed the challenges of recognising and speaking stories of shame. Attention is given to noticing vulnerability and the difficulty of speaking stories of shame and also to the role of witnessing in the relationship between the counsellor and the client meeting within a context of shame. This autoethnographic account offers itself as practitioner researcher. Knowledges produced in this research highlight the importance of considering first the role of shame in the life of a problem and second how it is to be positioned as a client in a counselling relationship.

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  • Emotional Well-Being and Secondary Traumatic Stress in New Zealand Youth Workers

    Takhar-Stapleton, Amber (2017)

    Masters thesis
    University of Waikato

    This study aimed to explore the relationship of STS and emotional well-being among New Zealand youth workers using a qualitative approach. Eleven participants were interviewed for the study using a semi-structured interviewing technique. The purpose of this study was to fill a gap in the literature about the impact of working with traumatised youth and to identify if youth workers were at risk and vulnerable to the effects of trauma exposure. Three aims were incorporated in the study to answer the research question. The first aim was to explore ways in which youth work may be associated with decreased emotional well-being and STS with the second aim of identifying symptoms and causes of decreased emotional well-being and STS. Lastly, the third aim was to explore how decreased emotional well-being is associated with the development of STS. The findings suggest the majority of participants experienced moderate levels of decreased emotional well-being and displayed symptoms associated with the effects of secondary traumatic stress. The results confirmed the first aim of the study which identified youth work as being correlated with decreased emotional well-being and STS. The results suggested decreased emotional well-being increased vulnerability to developing STS and therefore, the third aim of the study was also confirmed. Several themes were found in the participants’ answers which revealed youth work is associated with emotional well-being and symptoms of STS. This included emotional detachment, suppression, and numbing, helplessness, burnout and lack of resources to cope, social withdrawal, difficulty sleeping and changes in appetite. Risk factors which appeared to increase vulnerability included personal trauma, PTSD, countertransference, and empathic engagement. Organisational stressors were also identified as increasing vulnerability which heavily influenced participants and contributed to extreme stress and exhaustion. Findings in this study contribute to the knowledge of secondary traumatic stress as well as increasing knowledge about the emotional effects of working with traumatised individuals. Furthermore, the study helps to educate helping professionals and increases knowledge of youth work.

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  • Barry Barclay: the Reflection of Maori and Pakeha Identities

    Hilal, Emad Jabbar (2017)

    Masters thesis
    University of Waikato

    This Media and Screen Studies thesis tries to investigate the identifications of Barry Barclay (1944-2008) - a New Zealand filmmaker, thinker and poet, of Māori and Pākeha ethnic background - who identified as Māori in the second part of his career, in the mid 1970s. The thesis relies on Barclay's writing and other historical and theoretical material in the reading of his own films. The thesis arrives at an argument that even when Barclay chose to identify more with the Māori side of his identity, the Pākeha side took part also in the shaping of his film practices. Studying Barry Barclay along this line of argument has several benefits for Screen Studies. It, on the one hand, covers what is left unstudied by the scholarship concerning his representation of the Māori world such as the way he commented on Māori cultural and social concerns and acheivements in his films. The thesis studies Barclay's films from the time he started his identification with his Māori side in Tangaata Whenua (1974), Te Urewera (1987), Ngati (1987),Te Rua (1991) and takes The Kaipara Affair (2005) as a case study and a carrier of change in film practices and development in outlook.The other important contribution is the way he represented Pākeha, and how he developed his representation of them in time. This representation which is unstudied at all, is important to Screen Studies becuase it contributes to Barclay's theory of Fourth Cinema. This thesis shows how representing Pakeha, especially in Barclay's last film problemematizes his theory of Fourth Cinema, but ultimately, deals with applies it creatively. The representation of Pākeha gives insight into Barclay's interest in the Māori world, which is not a dogma or a merely ethnic affiliation as much as an attraction to a world-view that can solve major universal issues such as environmental problems. Above all, the way how Barclay worked out this representation in his films sheds light on one of the important examples of how film can take part in healing social damages such as the history of colonizing and marginalization of Māori people.

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  • The Development of Professional Learning Communities (PLCs) in the Philippines: Roles and Views of Secondary School Principals

    Capili-Balbalin, Wenefe (2017)

    Masters thesis
    University of Waikato

    It is widely recognised that principals play an indispensable role in the professional development of teachers in schools. In the Philippines, principals encourage teachers to participate in the traditional and most common approach to professional development such as conferences, seminars, workshops, and training. Despite documented benefits of these traditional approaches to teacher professional development, recent studies show that many teachers find them insufficient, inconsistent, and sometimes they do not necessarily address teachers’ classroom needs. There is a growing body of literature that recognises the importance of teacher engagement through professional learning communities (PLCs) as a new approach to teacher professional development. Unlike traditional approaches to teacher professional development, PLCs redefine professional development from programmes that regard teachers as passive learners to programmes that regard teachers as active learners who are responsible for their own professional growth. The study explored the roles and perspectives of secondary school principals in the development of PLCs in the Philippines. It is an underlying assumption that principals’ understanding of their roles in the implementation of teacher professional development policies in schools is central to the formation of PLCs. This raised two important questions that principals needed to contemplate: How did they view and implement national policies on teacher professional development in the school level? And, how did they perceive and establish PLCs in their schools? The study utilised a qualitative research methodology based on an interpretive paradigm. Through the use of semi-structured interviews alongside policy analysis, three main themes emerged: lack of continuing teacher professional development programmes in the Philippines; varying views of principals in the development of PLCs in schools; and, effective leadership styles as key to support continuing professional development of teachers. The lack of continuing teacher professional development programmes suggests that principals in the study failed to establish PLCs in their schools. This offers some important insights on the leadership experiences of principals in the implementation of national policies on professional development and how it affects their roles in supporting teachers’ continuing professional development. The study also reinforces theories around strong influence of school leadership in the formation of PLCs, particularly in developing countries such as the Philippines. This is an important issue for future work, as top-down leadership continuously predominates in school organisations in the Philippines. Further work is recommended to investigate the implications of this for the confidence level of principals in their leadership in the context of secondary schools in the Philippines.

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  • Adaptation to water scarcity in the context of climate change: A Case Study of the Nuku'alofa and Hihifo Districts, Tongatapu

    Fa'anunu, Jacqueline (2017)

    Masters thesis
    University of Waikato

    For the most part, PICs and SIDS are constantly reminded of their vulnerability to climate change. Often, the increasing portrayal of island countries as vulnerable does not necessarily address what causes that vulnerability. The UNFCCC and IPCC have sought to adopt more adaptation measures alongside mitigation especially in vulnerability assessments. In the context of Tongatapu, adaptation in the water sector still holds significant political and economic challenges. This thesis explores the rural-urban adaptation experiences of residents in Nuku’alofa and Hihifo, Tongatapu, to water scarcity in the context of drought and climate change. It also seeks to investigate the role of vulnerability in the provision of aid, in reference to the PACC (Pacific Adaptation to Climate Change) water project in Hihifo. In utilising discourse analysis and analysis of semi-structured interviews and focus groups consisting of participants from Nuku’alofa and Hihifo, a range of themes emerged on the complexities of vulnerability and adaptation to climate change in Tonga. Hence, I sought to identify the ways that people can adapt to water scarcity in the context of drought and climate change. I draw from post structuralism, cultural geography and the vulnerability theory to uncover the discourses present in the climate change literature. It was also important to incorporate literature on sustainability and indigenous knowledge as they support better adaptation capacity in not only Tongatapu but also all of Tonga’s water sector. In particular, I examine vulnerability from a local point of view versus the views of those at the national level. In doing so, local knowledges can help shape decisions on policies regarding water and climate change. Government documents on climate change in Tonga has progressed from a vulnerability point of view to a resilience and adaptation frame of thinking. However, adaptation in the water sector is not solely a problem based on natural variability and climate change. A huge part of water problems is largely rooted on political and economic processes. This underpins the accessibility of people to water resources. This problem needs to be addressed, in order to increase the adaptive capacity of people in the rural-urban areas of Tongatapu.

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